Explosive driven guillotine



Nov. 19, 1968 w, R s 3,411,401

EXPLOSIVE DRIVEN GUILLOTINE Filed April 26, 1967 /9 Q|Himiuumh ilml IINVENT OR /9 BARREL W HARE/5 BY Afro/Mr United States Patent ice3,411,401 EXPLOSIVE DRIVEN GUILLOTINE Darrel W. Harris, Colonial Beach,Va., assignor to the United States of America as represented by theSecretary of the Navy Filed Apr. 26, 1967, Ser. No. 634,813 6 Claims.(Cl. 89-1) ABSTRACT OF THE DISCLOSURE An explosive driven cutting devicehaving a guillotine blade capable of being lowered against a wire, rope,cable, tube, or like member for severing, the device being insertablealong a confined detonating cord explosive train at a plurality ofpoints whereby detonation along the train will serially effect alowering of the guillotine blade for severance.

Government interest in the invention The invention described herein maybe manufactured and used by or for the Government of the United Statesof America for governmental purposes without the payment of anyroyalties thereon or therefor.

Cross-reference to related application This application is related toapplication Ser. No. 538,902, filed Mar. 25, 1966, now US. Patent No.3,352,- 513, for Helicopter Rotor Shaft and Rotor Blade Severing Means.

Background of the invention The present invention is related generallyto a cable cutting device and, more particularly, to a means forsevering a plurality of cables in series through a single confineddetonating cord. In helicopter and other aircraft escape systems, it hasbecome necessary to completely separate the fuselage such that the crewoccupying compartment can be independently lowered to safety from theremaining portion of the helicopter or aircraft. Various meeans havebeen heretofore designed for severing the electrical wiring, controlcables and hydraulic lines in the helicopter escape system. Among theleading techniques used, are those of the shaped charge or of thecartridge actuated guillotines. Although the explosive shaped charge iscapable of severing along a single explosive train, large explosivecharges are required in order to insure complete severance of thecircumferentially spaced members of the fuselage and the positioning ofthe charge in relation to the member to be cut must be closelycontrolled. In addition, fragment shielding becomes necessary because ofthe unconfined nature of the charge. On the other hand, the guillotineseparation devices heretofore designed have been each equipped with acartridge for lowering the guillotine blade against the member to besevered. While these devices have obviated many of the disadvantagesinherent in the shaped charge separating means, their extended use inhelicopter and other aircraft escape systems is rendered impracticablein view of weight problems and difficulties in designing adequateself-arming means. Moreover, these separation devices each requireindependent actuation from separate live cartridges. The presentinvention seeks to avoid the disadvantages of the prior art devices byproviding an explosive driven guillotine blade which is lowered againstthe member to be cut as the explosive propagates along a confineddetonating cord. A plurality of units, according to the instant design,are installed along the cord in order to facilitate a cutting of thelines and cables in series.

3,411,401 Patented Nov. 19, 1968 Summary of the invention An explosivedriven cutting device consisting of a housing, a movable guillotineblade contained therein, and terminals of a confined detonating cordseparated by a gap and in contact with the guillotine blade. Propagationof explosive along the cord produces a shock wave at a cord terminal toboth lower the guillotine blade against a member to be cut, and, toactuate an adjacent cutting device along the cords as the shock wavejumps the gap.

It is therefore an object of the present invention to provide a cuttingmeans capable of severing a plurality of wires, ropes, cables, etc, froma single detonating cord.

Another object of the present invention is to provide a cuttingapparatus capable of being installed along any point of a confineddetonating cord explosive train which apparatus is completely inertuntil installation in the explosive train.

A further object of the present invention is the provision of a cuttingapparatus having a single moving element and being completely incapableof inadvertent actuation before installation in an explosive train.

Still another object of the present invention is to provide an explosivedriven cutting device having the unique capability of transferringexplosive energy therethrough.

Other objects, advantages and novel features of the invention willbecome apparent from the following detailed description of the inventionwhen considered in conjunction with the accompanying drawings.

Brief description of the drawings FIG. 1 is a partly broken away sideview of the instant design showing the guillotine, cord terminals,anvil, and object to be cut;

FIG. 2 is a top view of the FIG. 1 device;

FIG. 3 is a bottom view of the FIG. 1 device;

FIG. 4 is a side view of the FIG. 1 device;

FIG. 5 is a sectoinal view taken at line 55 of FIG. 1;

FIG. 6 is a partly broken away showing of the cord terminal;

FIG. 7 is a perspective view of the guillotine blade; and

FIG. 8 is a schematic view showing a plurality of cutting devicesinstalled along a detonating cord for severing a plurality of cables inseries,

Description 0 the preferred embodiments Referring now to the drawingswherein like reference characters designate like or corresponding partsthroughout the several views, there is shown in FIGS. 1 through 4 acutting device 10 consisting of a housing 11 having a slot 12 thereinfor permitting a sliding movement of a guillotine blade 13 as it islowered against a cable 14 or other object to be cut. A clear showing ofthe guillotine blade 13 appears alone in FIG. 7 of the drawings. Theobject 14 to be cut rests against an anvil 15 disposed along the lowerend of housing 11. As is apparent from FIG. 1, a cut-out portion 16 isprovided in housing 11 of a dimension sufficient to accommodate theobject 14. In FIG. 5, the guillotine blade 13 is shown maintained in itsinitial position at a maximum distance from object 14, by means of anylon head 17, adjustable through a set screw 18 mounted in the housing11. At opposite sides of the housing 11, a pair of explosive cords 19,terminating in explosive filled caps 21, are threadedly secured, asshown, or are otherwise attached to the housing. An enlarged view ofcord 19 is shown in FIG. 6 with part of the cap 21 broken away to showthe explosive content thereof. As in FIG. 1, the ends of caps 21 aremaintained apart so as to provide a gap 22, The explosive cord itself,while not a subject of the instant invention,

is preferably of the type of light weight and light powder graindispersion which operates on a shock wave principle and is commerciallyavailable from several sources under the name of Confined DetonatingCord.

In operation of the instant device, initiation of the explosive in cord19 from either direction is commenced from a source, not shown, and ispropagated to either of cap 21 whereupon the shock Wave at gap 22 willperform two functions. It will lower the guillotine blade 13 intocutting engagement with the object 14 and come to rest against the anvil15. The shock wave, at the same time, will jump the gap 22 and initiatethe explosive in the other cap 21 to continue the propagation throughthe other cord 19. As is evident from FIG. 8 of the drawings, a severingof an object 14 adjacent the leftmost cutting device 10' will beeffected in the same manner as just described. While a cutting of thesecond object 14 is taking place, detonation of the explosive will bepropagated further to the third adjacent cutting device 10 and furtherthrough as many cutting devices as are installed aroundthe circumferenceof the fuselage. Separation of the objects 14 in this manner isaccomplished by a clean cut through the use of a single moving part fora completely nonfragmenting severance.

The explosive driven guillotine of the instant design is a uniquecutting device of particular application for the severing of electricwiring, control cables and hydraulic lines in the helicopter escapesystem heretofore cited as a related application. Such a cuttingapparatus is a simpler design over those devices currently available,has fewer component parts, is smaller in size per unit, possessesgreater reliability and is of significantly less cost than any of theprior devices heretofore devised. The explosive driven guillotine has anexplosive charge of about onethird that required for a shaped charge.Its total weight is less than the weight of a shaped charge and requiresno backup structure. The instant device also has the unique capabilityof transferring explosive energy therethrough, and, therefore, can beinstalled along any point in a confined detonating cord explosive traineither in existing or newly assembled systems with little effort. Thedevice is inert until it is so installed in the explosive train therebyrendering it completely safe until installed. Although the explosivedriven guillotine has been designed for the helicopter escape system, itcould be used in any military or civilian application requiring reliableseverance of wiring, cables, tubing, etc.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that Within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

1. A cutting device capable of severing a cable, wire, rope and thelike, from an explosive detonating cord, said device comprising:

at least one housing;

a moveable guillotine blade disposed within said housing capable ofbeing lowered against the object to be cut;

detonating means, said detonating means comprising a detonating cordhaving a pair of explosive caps mounted on the ends thereof; and

connecting means linking said detonating means to said housing in aspaced apart relation so as to provide a gap across which a shock waveis caused to jump thereby lowering said guillotine blade.

2. The device of claim 1 wherein a plurality of housings are providedalong the explosive detonating cord whereby propagation may betransmitted through each housing by said shock wave thereby effecting aseverance in series of objects to be cut.

3. The device of claim 1 wherein said guillotine blade contacts thesides of said connecting means and is maintained in contacting relationby a screw head mounted in one face of said housing.

4. The device of claim 3 wherein said housing, at a third side thereof,is provided with an open slot for receiving the object to be cut.

5. The device of claim 4 wherein said housing is provided with alongitudinally disposed anvil mounted through the walls of said slot ata distance from said guillotine blade so as to provide a surface againstwhich said guillotine blade comes to rest after severing the object tobe cut, v

6. The device of claim 5 wherein a plurality of housings are providedalong the explosive detonating cord whereby propagation may betransmitted through each housing as said shock wave jumps each gapthereby effecting a severance in series of objects to be cut.

References Cited UNITED STATES PATENTS 3,032,356 5/1962 Botsford 10249.5X 3,139,031 6/1964 Schroter et al. 102-49.5 X 3,246,396 4/ 1966 Templeet a1. 3,326,127 6/1967 Schimrnel 10227 SAMUEL W. ENGLE, PrimaryExaminer.

